Automatic door operator having automatic means for manual operation



July 28, 1953 Filed Dec. 17, 1947 C W. BASSETT ET AUTOMATIC I5OOROPERATOR HAVING AUTOMATIC MEANS FOR MANUAL OPERATION ll Sheets-Sheet 1 F"I I0 0' IO 0' I. I I

I I I f ""21; [g1 INVENTORS Cwws I/V. Bnssrrv JOHN H VA/wn-R l/EERALBERY E. WEIQELE ATTORNEY July 28, 1953 c. w. BASSETT ETAL AUTOMATICDOOR OPERATOR HAVING AUTOMATIC MEANS FOR MANUAL OPERATION 11Sheets-Sheet 2 Filed Dec. 17, 1947 va mwm MW NNN.

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IN V EN TORS Fynus W BASSETT on! H. VANDER VCER ALaERr E; WelqELEATTORNEY July 28, 1953 c. w. BASSETT ETAL AUTOMATIC DOOR OPERATOR HAVINGAUTOMATIC MEANS FOR MANUAL OPERATION ll Sheets-Sheet 5 Filed Dec. 17,1947 I 5 7w 5 mi y E MMW Q E Hwy 4 N mu m, W \k hr ANA w A Mm w 02 AJuly 28, 1953 c. w. BASSETT ETAL 646, 8

AUTOMATIC DOOR OPERATOR HAVING AUTOMATIC MEANS FOR MANUAL OPERATION 11Sheets-Sheet 4 Filed Dec. 17, 1947 INVENTORS (mus W BAssrr-r J01!Hl/AIYPIR Vern ALocRr E2 Wg/qe-LE @1 4 @MM A TTOlP/VEY y 8, 1953 c. w.BASSETT ETAL' 2,646,981

AUTOMATIC DOOR OPERATOR HAVING AUTOMATIC MEANS FOR MANUAL OPERATIONFiled Dec. 17, 1947 ll Sheets-Sheet 5 O) o m co 0 ch 10 01 8 00 H m l mon D N 28 I q I III\ n a J In *1 I I o N g N 1 m 03 O F m w m V k6 on IOm N (O O\ D m H N 2 s 00 t f t 0 n m :1 vnfl iif is si-r P Q JOHN H.VA/YDE'R Vssn O \O ALBERT E. Ws/qnE tfi N BY 9 0 w wm l ATTORNEY July28, 1953 c. w. BASSETT ETAL AUTOMATIC DOOR OPERATOR HAVING AUTOMATICMEANS FOR MANUAL OPERATION ll Sheets-Sheet 6 Filed Dec. 17, 1947 awwmwwa Wwum g & Ji om M Y. B Q Rm? 5 Q\ 3. 0m 0w mo I m m m A TTUZP/VEYJuly 28, 1953 c. w. BASSETT ETAL AUTOMATIC DOOR OPERATOR HAVINGAUTOMATIC MEANS FOR MANUAL OPERATION Filed Dec. 17, 1947 ll Sheets-Sheet7 INVENTORS Crnus W BASSFTT JOHN H. VAIYDER YEA-R1 AL'BERT E WeIqeLe-ATTORNEY Ju y 8, 1953 c. w. BASSETT ETAL 2,646,981

AUTOMATIC DOOR OPERATOR HAVING AUTOMATIC MEANS FOR MANUAL OPERATIONFiled Dec. 17, 1947 ll Sheets-Sheet 8 N3dO 21000- IN V EN TOR. Cykus VVBAssz-rr Jon/v H VAHDER l EFR By ALBERT E. WEI ELE A TTOPNE' Y 2,646,981OPERATOR HAVING AUTOMATIC MEANS FOR MANUAL OPERATION l1 Sheets-Sheet 9Filed Dec. 17, 1947 h v Wg Q Q) I 2m QN a? mmm Q w \wom y mmwz. N FUImHm WWW A m 3m wwm mmvflovw 9% 0mm 0 v. mmm T M I r w A m3 o? 7 mg n SE m II mfi 2% mm m I @mwam 3 m if \E H III $.mv2 0 @J \MIWI I R FI wav.9 I I amm N8 3% 6% 8m 3 6 2w 2 I e mg m IE3 3; T WQ J W P M 8w l| 1v Iaq a I HIIIII. IIIIIII I x 8w fiq 0 3 w 1% 0% Sq mm; I Q n a I m g RX 3mWW m I SI 2% $1 2 July 28, 1953 c. w. BASSETT EI'AL 2,646,981

AUTOMATIC DOOR OPERATOR HAVING AUTOMATIC MEANS FOR MANUAL OPERATIONFiled Dec. 17, 1947 ll Sheets-Sheet l0 u... 5% W i a a Q D\ A? mmm wwm Hfim 5A nV mm M WEN/3N 5 8m 5% Sm NS I 8m Nam/N v m w? @R w. u D. ii I m5 N n Q mw m 03 q m3 Q H @mm 3m 0 m g w 5 G 6 $5 Sm N2 2% m3 m8 mm 0 oSm Q3 m om 8m 0% 2w m tl I- 4.. mm}: omm\ 1 own & r illii S A mum 3m 0mmSq 9 gm 0 3m 3w m A TTOiP/VEY J y 8, 1953 c. w. BASSETT ETAL 2,646,981AUTOMATIC DOOR OPERATOR HAVING AUTOMATIC MEANS FOR MANUAL OPERATIONFiled Dec. 17, 1947 11 Sheets-Sheet ll IN V EN TOR-5 m'us W Buss-r1-Jou/v H. Mwasn VEFR BY ALaER-r'. WEIGE'LE by a passenger.

Patented July 28, 1953 UNITED STATES PAT-ENT o arr-ca AUTOMATIC DOOROPERATOR HAVIN G 'fiUTOMA EIG S FORLMA'NUAL 10P- ERATIGN "Cyrus W.Bassett, Monmouth County, John H.

Vander Veer, Union County, and 'Aib'ert Weigle, Essex County, N. -'J.,*assignors, by rnesneassignments, to Nation-aI 'PncumaticCo inoBotonQMass, a corporation of Delaware ApplicatiomDecemher 17,1947,,Serial No.1 92,258

warm. I

This invention relates to automatic fdoo'r operators having automaticmeans for manual operation.

"The invention is described here as developed for the operation of theend doors of vehicles "such'as railroad cars. "The invention has appli-"cation in many other connections.

'Thepractice of conditioning the air of railroad cars'lias createdthe-necessityior providing tighteriseals'for the door opening, For'thispurpose,

"iheaVier-doorshave become necessary forpre- "venting leakage of thecooled air. L'This requirement,.and the tight fitting of thedoor intoitsframe, when closed, necessary for this purpose,

- imum.

In situations where apparatus-automatically 'to operatesuchdoors hasbeen made effective,

there mayarise the reverse situation where the motive means for suchapparatus --be8OI-neS--d-i-S abled. In such instances, it generallyisdesirahle totprovide means automaticailytdclose the-door, as,"forinstance, a spring. Yet, at the same-time, .it would-not bedesirableto'shave suchzspring function inconjunctionw-ithqtheapparatusautomatica'lly to operate-the doon continuously. It isdesirable to make such spring-and its" vassociated apparatus powerfulenough to operate the door to closed position-easily,-and.yet-lto-becapable of manual operation for-opening:thesdoor.

The apparatus must be:such -that an. ordinary: person will be able tocounteract-the mec-hanicahelements, to assure that sucha-door wil-tnotbecome a dangerous, insurmountable barrier -zt esuchaa 'degreeas tobe.impractica-bleior use: on suchveihicles. For instance, in=one .case,a gpneumatic engine is used for opening and :closing the idoor inresponse to :actuation .of initiating members pneumatic engineshouldiail,for some reason, it is requisite that the passeng-erbeenabled toover-"come the resistance of the usual elements-in- "cludingthe pneumaticengine, in order to open "the"'d'oor.

It is'an object of the invention to provide means," association withapparatus automati- If the power or control ior the deenergization of.the motivemeans for therappa'ratus, will function so that the doormay-he used "as an ordinary spring closed door,.as ii.no such apparatushadbeen provided v:foriitssautomatic operation.

It. is an object o'f'theinvention to proyide appa'ratus,iunctioningiinconjunction with atdoor "having motive means for openingit-at. alsignal from-a passenger, which-apparatusrisskeptanormally outof action, and which, immediately-upon disabling of the ,powermmeansiortbe .door operating motive means, .comes into .actionzto aasSur-ethat the door willinormallyabe .elosedpandi yet to. permit thedoor to bemoved toopenz position as if the doorwerecontrolledlonlybyvthis-zapparatus, and without regard for the normaleffectiveness ofthemotive means.

Other. objects .of theinvention will be -set: forth hereinafter, .orwillbe-apparent :fromthe: description and thedrawings-in-which areillustrated embodiments exemplifying the invention.

The invention, however, is notinterrdeddo be restricted to-anyparticularconsmuction, :orrany particular arrangementof parts, :or anyparticular application of any such construction gen-larrangementiofparts; or anyispecific method. ofmp- Aeration or use, or 'any of the:various details thereof, -even where specifically shown eanidid-escribed herein, as -.-thesame "may be imodified in variousparticulars, -.or 1 may be: applied insmany varied relations, withoutdeparting :from spirittand scope .of the claimed invention, of which theexemplifying embodiments, .fhenein shown and described, are intended01113 2170 be illustrative, :and only for thegpurpose l'oficomplyingwith the requirements of the iStatutes ztor disclosure of an operativeembodiment, but not to show allwthe yarious iorrn-s can'd modificationsin which the invention might be'iembodie'd.

On-the drawingsiin'which the isameirefereirce characters refer to theeams .zgparts :throughout,

v and in whichisrdisclosedsuclnpraetical construc- Fig. l..is*an-:elevational yiew illustrating arr-assembly including'z-a 'cloorxconstruction associated with 4. a {door ,frame, the assembly 1 including:ap-

paratus, ,for the-operationsof the doorgandaem- ,bodyingtthe invention;a .portion of the doormanstruction being broken awayin:section;1-.;o-.;i1;lustrate the arrangement. of the-door latchswitch, and the door construction being broke-n away along itsmid-sectioniorclarity;

"Figjla is'a vertical cross-sectional yiew,..substantially on. the line.la"1a o'f Fig.. 1, toi-1lustrate "thepost' construction for the 'door;

Fig. 2 is a plan view of the door operating apparatus shown in Fig. 1,the closed position of the door being shown by dotted lines;

Fig. 3 is a detail vertical cross-sectional view, substantially on theline 33 of Fig. 2, and to enlarged scale, illustrating the constructionof the door-operating engine and associated parts,

one of the cylinders being broken away to foreshorten the view forclarity, and the retaining clamps being shown in part by dotted lines;

Fig. 4 is a vertical cross-sectional view, substantially on the line 4-4of Fig. 3;

Fig. 5 is a vertical cross-sectional view, substantially on the line 5-5of Fig. 2, and to enlarged scale, illustrating the construction of the'auxiliary engine;

Fig. 6 is a vertical cross-sectional view, substantially on the line 66of Fig. 5, some of the parts being shown in elevation for clarity;

Fig. 7 is a vertical cross-sectional view of a portion of the auxiliaryengine shown in Figs. 5 and 6, and parts associated with the engine atone end, in order to illustrate the arrange- 'ment of the loose motion,shown in part in elevation, the normal position of the pin and itsassociated piston rod in the operation of the apparatus being shown bydot-and-dash lines;

Fig. 8 is a detail of the plan view of Fig. 2, to enlarged scale, partsbeing broken away, il-

lustrating details of the construction of the apparatus;

Fig. 9 is a detail, vertical cross-sectional view, substantially on theline 99 of Fig. 8, parts being shown in elevation for clarity;

Fig. 10 is a vertical cross-sectional view, sub- Fig. 13a is a detailelevational view, to reduced scale, to illustrate the position of anoperating plate for the apparatus of Fig. 13, the apparatus being brokenaway to foreshorten the illustration, and the door being broken away;

Fig. 14 is a vertical cross-sectional view, substantially on the lineI4--I4 of Fig. 13;

Fig. 15 is a Vertical cross-sectional view, substantially on the linel5|5 of Fig. 13;

Fig. 16 is a horizontal cross-sectional view,

substantially on the line l6-l6 of Fig. 13, il-

lustrating the association of parts of a detail of the apparatus;

Fig. 1'7 is a detail cross-sectional view, substantially on the linel'|i1 of Fig. 14, and to enlarged scale, to illustrate the constructionand arrangement of parts in the auxiliary engine of Fig. 13, certain ofthe parts being illustrated as if in a vertical cross-sectional view;

Fig. 18 is a vertical cross-sectional view, substantially on the linei8l8 of Fig. 17;

Fig. 19 is a vertical cross-sectional view, substantially on the lineIii-l9 of Fig. 14, and to enlarged scale, illustrating the constructionof the main engine;

Fig. 20 is a schematic diagram, illustrating the arrangement of thepiping for the supply of air under pressure to the various parts of theapparatus of Fig. 13 and Fig. 21 is a wiring diagram for the apparatus 4of Fig. 13, parts of the apparatus being shown schematically.

A door I0, as shown on the drawings, is positioned at an opening I2 indoor frame I4, forming a part of an end wall of a vehicle, as, forinstance, a railroad car. At opening l2 and in association with frame M,a threshold l8 and a rail 20 may be associated. The threshold may beformed to provide a bearing for a pintle 22 the rail is mounted a baseplate 28. provides a foundation for the apparatus to be up on thethreaded end of rod 50.

extending downwardly from the bottom of the door. The door may beconstructed in any desired manner. In the instance shown, the door is ofmetallic construction, the pivoting end 24 being rounded, and having ashaft 26 fitted into the body of the door at that point. The shaftextends above the top edge of the door to a position above the rail 20.At the top face of Plate 28 described. In the particular instanceillustrated, a main door actuating assembly base plate 30 is mountedupon plate 28. Then, at one end of plate 30 is formed a hub 32. Shaft 26extends through an opening in plates 28 and 30 and hub 32.

Hub 32 is formed as a part of a ball bearing race. The inner portion ofthe ball bearing race may be a part of the shaft. A plate 34 closes therace. A collar 35 fits into an opening in plate 34, and rests upon theball retainer 31, and, in turn, serves as a support for the hub 36 of asegment gear 38 received on the shaft. The gear may be formed as a partof hub 36, and is locked to rotate with the shaft. Suitable means, suchas lock nuts, serves to retain the gear against movement along theshaft.

At the end of plate 30 away from hub 32 is formed a boss 39 in anopening in which is fixed a pin 48. Upon this pin is mounted a hub 42'of a spur gear segment 44. Segment 44 is permitted rotation upon pin40, and is held against separation from the pin by means of suitablewashers and cotter pins. Segment gear 38 and gear segment 44 areproportioned so that, on the centers of shaft 26 and pin 40, they areenmeshed, and function as a drive to multiply the arcuate movement ofsegment gear 38, and, therefore, of door 10, secured to move therewith,to arcuate movement greater than that of gear segment 44.

Hub 42 includes an arm 46 formed with a socket 48 to which may extendthe end of a rod 50. Rod 50 is held in place with relation to arm 46 bymeans of lock nuts 52 tightened Lock nuts 52 provide for adjustment ofrod 50 relatively to its associated apparatus, and especially indetermining the position of door [0 with relation to the limits set forengine 54. Rod 50 is provided pivoting connection with a connectorassembly 56 by any suitable means, such as a pin extending through abearing hole 58 in ear 60 on rod 50 and a similar hole 62 in the end ofassembly 56. Thus is provided means for pivoting movement of the partswith relation to each other.

Connector assembly 56, which provides connection between rod 50 andpiston rod 64, may include a frame 66 having a two armed yoke 68 at oneend. Ear 60 is received between the arms of the yoke; a pin is receivedthrough the respective holes 58 and 62. Frame 66 is somewhat of the formof a U, one arm 10 of the U having a passage 12 formed therethrough. Rod14 extends through passage 12. In the these parts together.

to limit movement of the rod with relation to frame 66. Beyond arm 10, apair of lock nuts plate 28.

other arm 16 of the U is formed a seat tore- -ceive the end 18 of rod 14formed to permit are provided on rod 14 as another limit for movement ofthe rod. The limits; of movement of rod 14 with relation to frame 66 arethus set by collar 86 and lock nuts 90.

Rod 14 terminates ina threaded portion which I is-received in a threadedsocket 92 formed in an L-shaped connector 94. The rod is locked in thatposition by means of a suitable lock nut. Connector 94 has .a forked arm96, the parts of which are provided with openings '98. Between the partsof the forked arm, the end piece I00 of piston rod 64 of engine 54 ispositioned and pinned for pivoting movement. While the power meansillustrated is a differential pneumatic engine, it will be understoodthat any other suitable power means capable of energizing the apparatushere described may be used. In the construction shown, engine 54 ismounted upon engine is held in place by straps I02 which encircle thebody of the engine, and are anchored to suitable brackets provided forthat purpose upon plate 28.

At a position on plate 82 beyond the bounds of spring 80 is positioned-acontactor I04. Contactor I04 is here shown in the form of a headed screwpassed through an opening in plate 82, held adjustably in position bymeans of lock nuts I06 positioned on opposite sides of the plate. Inthis manner, the position of head I08 of the screw is adjustable withrelation to button I I0 or other suitable actuator member of a sensitiveswitch I I2, which is actuated upon very slight movement of an actuatingdevice such as button I I0. Switch H2 is secured in position withrelation to head I08 in any preferred manner. In this case, it is heldin position by a screw II4 which passes through the insulated body ofthe switch and is received in a threaded opening H6 in arm 16.

Switch II2 may be a microswitch having a very light spring in itscomposition. Spring 80 is of a construction heavy enough that, ondelivery of force of usual degree to arm 96 through piston assembly II8of engine 54, spring 80 will act as if it were a rigid member, and willtransmit force directly from rod 14 to arm 16, and thus to rod 50,without appreciable compression of the spring. However, if resistance tothe movement of door I0 is encountered, as, for instance, if someonegets in the way of the door as it closes, and should resist completionof the closing movement of the door, power will continue to be deliveredby the engine through connector 94, and plate 82 will continue to move.Spring 80 will resist such movement, and will be compressed slightly,just sufiiciently so that head I08 will engage button H0 .and actuateswitch II2, causing that switch to afiect the In the specific structureshown, the

6 circuit it controls in :a manner to be described hereinafter.

Engine 54 may be of any suitable construction. The engine for carryingout certain. purposes in connection with apparatus of this type is shownto include a large cylinder I and a small cylinder I22, held together bya coupling I24. secured to the two cylinders in any desired manner, as,for instance, by suitable threading. A passage I26 in the coupling whichis positioned to bedirected toward cylinder I20 also communicates with ascrew threaded port I28 with which a conduit I30 may be connected.

Within the two cylinders is mounted. piston assembly III] which, in thiscase, includes a tubular member I32 having a hub I34 extending from'itssmaller end into bore I 36 of member I32. This :hub has an openingI38 therethrough into which is received a member I40, the end 'of whichextends through opening I36 and receives a nut I42 to hold member I inplace with relation to the piston assembly. Portion I44 of member I40 isprovided with means to prevent leakage of air past it, and also with-means for locking the parts of piston I46 with relation to member I40.In this case, the parts are anchored against a shoulder I48 formed atthe end of member I32 outside of opening I38.

Around portion I44 are'assembled the elements, including the leather cupmember I50 and the usual compressor parts of piston I46, the parts beingheld in position by suitable means, such as a lock washerand a lock nut.

Leather cup I50 may then function in connection with small cylinder I22.A lubricating ring I52 of any suitable type may be associated with cupI50. Beyond portion I44, member I40 becomes end piece I00 for connectionto forked arm 96.

The end of member I32 removed from piston I46 is enlarged into a headI54 which is recessed for the reception of packing I56. Bore I35 isthreaded at this end to receive the threaded neck-I56 of compressor IEO.Between compressor #60 and the end wall of head I54 is received aleather cup member I62 for a piston I64 to move in the larger cylinderI26. The leather cup member is held in place by any suitable meanssuchas a clamp washer I66.

its ends seated around hub I34 and against the end of member I32 at thehub. The other end of the spring is seated against enlarged section I12.Thus spring I16 tends to drive sleeve I10 out of bore E36, and isstopped in its movement in one direction by-engagement of shoulderI14'against end face I18 of neck I50.

Sleeve I10 is formed with a passage I extending the greater part of itslength. Openings I02, at one end of passage I80, provide communicationbetween passage I 80 and cylinder I20. in the wall'of tubular memberI32, one or more openings I84 are provided for direct 0011111111111-cation between bore I36 and the chamber outside-of-member I62 in bothcylinders as the piston assembly moves within the engine.

Beyond openings I82, sleeve I10 carries a'valve member I86 which maybeheld in place by any suitable means, such as a securing device I68.

Valve member I36 may include a valve plate I00 havinga pairoirecesses'tlz' at opposed faces. In

these recesses are positioned valve seating -mate sor I60.

.a conduit 2 68.

rial of. any suitable composition. On one face, the material provides avalve seat I94 for engagement with a valve seat I96 formed on compres- Avalve seat I88 at the other face of member I86 is positioned to engagewith a seat 208 formed in an end cap 202 threaded or otherwise retainedin position at the end of cylinder Seat 200 surrounds an opening 204which leads to a threaded port 206 to which is coupled A by-pass duct2I0 opens into cylinder I20 beyond seat 200 and communicates withopening 264.. The effect of flow through duct 2I0 may be controlled by aflow restricting member 2I2 threadedly received in duct 210.

In the operation of the engine, air is supplied constantly to bothcylinders I20 and I22 through port I26, by means to be described, whenthe air and electric power means are working properly.

.Air entering at port I26 acts upon both pistons Since piston I64 is thelarger, the

I46 and I64. piston assembly will be caused to move toward cap 262.Movement in this direction, as Will be seen from the drawings, causesthe piston assembly to move into the engine, thus drawing connectorassembly 56 with it, and causing door I to move to open position.

On certain occasions, as determined by the operation of the apparatus,air is admitted not only at port I28 but also at port 266. Now thedifferential of pressure is in the other direction, since air pressureis now acting upon both faces of piston I64 as well as upon the one faceof piston I46. Now the piston assembly will reverse its direction ofmovement, and push connector assembly 56 in the opposite direction, andwill continue to do that until the door is closed, provided interferencewith the movement of the door does not take place.

When port 206, by apparatus to be described, is open to the atmosphere,and air under pressure is being delivered to port I28, the pistonassembly rushes under the full impact of pressure between pistons I46and I64, to move the door to fully open position. This movementcontinues, with the full openin of port 206 available for this purpose,until seat I98 engages against seat 200, thus cutting off unrestrictedflow of air to the atmosphere from cylinder I20. Now air may pass onlythrough the restricted passage provided by duct 2 I0. At this stage, itshould be noted that throughout the operation of the apparatus, whensleeve H0 is free of seat I96, air may leak directly from the chamberformed around member I32 through openings I84, into bore I36 and passageI80, and then into cylinder I through openings I82. Thus, even thoughsubstantially all the air in cylinder I20 was exhausted to theatmosphere as soon as port 266 was opened, now that port 206 is closedby the engagement of seats I98 and 200, and the only outlet for air fromcylinder I20 is through duct 2I0, this leakage will assure that some airunder some pressure will be present in cylinder I20 throughout continuedmovement of the piston assembly to the position where the door is fullyopen. Thus, if anyone should interfere with the opening movement of thedoor at any of its stages, this leakage of air into cylinder I26 willbuild up a pressure within cylinder I26 and against piston I64 to assurethat, when this resistance to the opening movement is released, the doorwill not jump in the opening direction, but will continue smoothly inits movement to fully open position. Thus the danger that someone usingthe door will be struck by the door on such release is removed. The

building up of pressure in cylinder I20 thus counteracts the built upforce from the resisance interposed to the continued movement of thedoor.

Now, as the door tends to move to fully open position, sleeve I10continues to compress spring I16; seat I98 continues in engagement withseat 200. During all of this operation, air leaks into cylinder I20through openings I82, even after openings I82 are covered up by theirmovement within passage I66, since the fit of sleeve I10 within passageI68, while close, is not close enough to prevent such air leakage. Now,however, when seats I94 and I96 engage, the movement of the pistonassembly has been completed, and further leakage of air from bore I36 isstopped.

On the other arm 2I4 of connector 94 is provided a bearing opening toreceive a pin 2I8, held in position in any suitable manner, and alsoreceived in an opening in the end of a link 222, so that this link maymove with piston assembly I I8. Link 222 may be made up in any desiredmanner, with adjusting means for its length, terminating in a section224 having a slot 226 to receive a pin 228 fixed to an arm 230 whichextends through a slot 232 in a wall 234 of a cylinder 236 of an engine238. Slot 232 provides limits for the movement of arm 230 and rod 240 towhich the arm is secured in any desired manner, as, for instance, bythreading the end of the rod, passing that threaded end through a holein the arm, and locking the arm in place by a suitable nut on thethreaded end of the rod.

Engine 238 may comprise a pair of cylinders 236 and 242, held togetherin alignment in any desired manner, as, for instance, by the provisionof threads between a coupling 244 and the cylinders. The coupling mayhave a Wall 246 provided with an opening 248 through which may pass rod240. Within cylinder 236 a piston 250 may be retained in position,spaced from arm 230 in any desired manner. In this case, the piston isactually a cup, acting merely as a guide. At the end of rod 240 withincylinder 242 is a piston construction 254 which may take any desiredform so that a leather cup 256 is retained in position to cooperate withthe walls of cylinder 242.

Rod 240 at that end is tapered and then threaded to receive acup-retaining assembly which backs leather cup 256 against a ring 258which, in turn, holds additional packing 260 which is backed up againsta spring retainer 262. This retainer is held in position upon rod 240 bya snap ring 26I, and is itself threaded to receive and retain a sleeve264 which extends into the bore of cylinder 242. A spring 266 is engagedbetween retainer 262 and, at the other end of cylinder 242, against wall246. Sleeve 264 functions to keep the spring properly aligned so that itcan be compressed in the manner to be described.

End cap 210 is secured on cylinder 242 in any suitable manner, the caphaving a port 212 communicating with a duct 214 leading to a threadedopening 216 to which a conduit 218 may be con nected. Engine 238 is heldin place upon plate 28 by any suitable means, as, for instance, brackets280.

Conduit 218, by suitable conduit means, is connected with conduit I30;from the union of the two conduits, a single conduit 282 leads to anelectrically operated valve 284, commonly known in the industry as amagnet valve. This valve may be of any desired construction, but, inthis case, valve 284 is constructed so that, when electrical energyisappliedtothevaive; the valve" will supplyair under-pressure from-asuitable reservoir, conducted to" the apparatus: through: line suchcircumstances, piston construction Z54 will move soas to compressspringi-iifi; moving arm 230 to the limit of slot 232, and-thus movi n'gpin Z28 to'the extreme right handendof" slot 226, as illustrated in Fig.11'. On the other hand; if, after the apparatus has been" energized,power should fail for any reason,- valve 28 1 will be deenergized, andair will be permitted to exhaust Sprung-'26s will act to move frontcylinder 2 52 piston construction 254 toward cap 2T9; Pin 223', which,when piston construction 2'54-was effective; had been moved to theright, asshown in Fig; 1-1, to engage-with, or tube closely adjacent,and Wall 288-- of slot 226; will now, when valve- 234% is deenergized,move to 1 the left-hand end-of slot 226; as shownin Fig. '7, whereitwillengage end wall 2%" of slot 226-; When pin 228' was held" in theposition of Fig. 11, when the valve-was energized, the movement of link222' was without efiect as pin 22'8was'out of the range of the ends oftheslot, and moved only within the slot without engaging the end' wallsof the slot to cause any movement of'the' link, regardless of thedegreeofmovement of link222 under the action of connector 94 driven bypiston as.- sembly H8; With the release of air pressure. upon pistonconstructiorr2543 ifdo'or'lfi had been opened-by engine St'prior to suchdeenergization of valve 286, spring 266'wou1d now become effective, pin228 engaging wall'29t, andimoving link 222"; and thereby frame 65,and'through it, segment gear38 and the door secured to move with.

it, to move the-door topclosed position. Thereafter -1e door couldbeoperated as anordinary spring closed door, since piston" construction254 no longer-would interfere with the operation of.

the spring, and pin 228 would remain engaged against'wall 29! The airsupplied; for conduit 208 is obtained. from another magnet valve .292.Magnet. valve 292 i's'preferably of the type Which,..whenenergizedelectrically, opensla .port tothe atmosphere, so-thatairwi'l'lexhaust from conduit 268. When,

howevei xelectric power is cut off, this valve 292 operatesto open aport leading,.by suitableconnection's; to conduit 282', and then tosupply air underpressure to conduit 2&8 so long as valve. 2% is'energized. When: air is. supplied toconduit 258;: the piston assemblyHSiscaused to move to closethe door. While the airsupply. to. valve 292may be directly from the reservoir, it has been found very desirable tocontrol all air supplied for the operation of the apparatus by a singlevalve 28 i. In this" manner, while valve 254' is energized, air issupplied to the" apparatus for the: operation ofen'gine 54 as well asfor'supplying air constantly to auxiliary engineZtt. When powerfailsand; therefore, valVe-284-is deenergized, the air supplied" tothe entireapparatus,

'- withdrawing the bolt from thestrike.-

10 including valve 292, is cut off. At this stage;- the apparatusismadeeffective tooperate without pneumatic means.

In order to control" the operation of't'his apparatus in accordance withthe passage of persons through the door, suitable control means may bepositioned either upon stile 2 8 .3 of 'fr-ame it, oruponthe dooritself; It is desirable'that theperson coming to the door shouldproceed. to" operate itin the same manner as that with whichhe has beenaccustomedin the pasti- For this-- purpose, suitable actuatingmechanismmay be positionedupon the door itself; Such'mecha- I'llSll-lisshown in this case in conjunction with means for withdrawing the bolt2 96- from the strike 2-385 Bolt 296 i'sshown to-be slidab'le ina=housing 3%; and tb-he-returned to 'nor-mal posi tion hysuitable resilientmeans. Carried by-thebo-l't' may be a finger S'EZ positioned t'o' engagewith art actuator 3%; which may take thef'orm of a button extending froma casing in which'are housed' the elements of aswitch-305i Thus, whenthe usual'- handleor push plateis engaged and rota-ted or pushed by theperson attempting to l openthe-door; bolt 29B will beslid tobring fingerSW2 into position for driving actuator 304' to close the circuitto-bedescribedl The time consumedin closing the circuit of switch- 306'will be substantially the same as that consumed in The-ener gi'Zat-ionof" the circuitwill thus be completed at thetime the door is releasedfrom the engagement of 'bol't-and strike'so that the-operation-to bedescribed maythen proceed seriatim without further control of the personseeking to" pass through" the door opening;

The circuit'complete'd by switch 306 is shownin the wiring diagram ofFig; 12', where-it will be seen that switch 3 is in the circuit of"aswitch 368 which is in the nature of atimedelay relay; The wiring fromswitch 306 may" be carried fromhousing 369' through door I0- through thebore 31tprovided in shaft 26; and them up through the bore toa positionabove" plate 28t'o enter into the wiringatthis-positionwhere'the'controls for the-door operatingmechani'sm are"located. Switch 308* may takeany desiredform'. As shown in Fig; 12, itmayd'nclude a spindle 312* functioning as the plunger of a" solenoid314. Normally the spindle; oy-meansof a'-spring:3 I 6'; isatthelowermost posit-ion'at whichits-insulatedend s-la keeps contacts 320'and 322 in position to"- break the circuit between them; The spindle, atits upper end; engages against" H abellows- 324 or similar air chamberforming means. One-wall of the bellows has a perfora' tion 326 formedtherein. A- threadedly adjustablemember328 provides meansfor varying thepermitted to move under the action of" spring This movement, however,will be retarded 316iby'the'movement of air into-the-bellows throughperforation 326; This air movement can be adjusted for the purpose oftiming the return of the spindl'eto its lowermost position. When Just assoon as 1 l the spindle reaches its lowermost position, end 3| 8 willbreak the circuit across contacts 320 and 322.

Supplied with the apparatus is a switch 330 which has three positions,which are here designated as Door open position, the Manual position andthe Automatic position. This switch, which may be considered, for thepurposes of this illustration, as the main switch of the apparatus,controls power from the power mains 332 and 334. The switch is showndiagrammatically as its specific construction does not enter into thespecific phases of the invention, and may be considered to have asliding contact 336 to engage with a plurality of terminals 338, 346 and342. One terminal 338 is connected to a terminal 344 on a terminal board346, and from there to contact 326. The other terminal 342 of switch 330is led to a terminal 348 on terminal board 346, and then to the othercontact 322.

Terminal 350 on board 346 is connected to main 334. To this sameterminal is connected one end of the solenoid coil or switch 308 as wellas the ends of the solenoid coils of valves 284 and 292. Terminal 354 onboard 346 is connected to one terminal at switch 366, that same terminalbeing connected to the other terminal of the coil of switch 368. Theother terminal at switch 306 is connected. to terminal 344. Terminal 344is also connected to one of the contacts of a reversing cut-out switch352 mounted to be operated by the door operating mechanism in a mannerto be described. Terminal 344 is also connected to the other terminal ofthe coil of magnet valve 284. Terminal 348 is also connected to theother terminal of the coil of valve 292. The other terminal of switch352 is connected to the final terminal 356 on board 346, and terminal356 is also connected to one of the terminals of switch H2. The otherterminal of switch H2 is connected to terminal 354.

Now the circuit can be traced simply. Switch 333 may be positioned inany desired relation to the car with which the door operating apparatusis associated. It is intended to be set by an operator, such as theporter usually assigned to such cars. The usual setting of such a switchwill be that where the two terminals 338 and 346 are connected together,and terminal 342 is left unconnected, the Automatic position. When themain switch for power supplied to the apparatus is closed, valve 234 isimmediately energized, causing air to flow to conduit 282.

This results, if no other actuation has taken place up to that pointexcept the setting of switch 330 as just indicated, in causing pistonconstruction 254 to compress spring 266, and thus place the operatingparts associated therewith, that is, pin 228 and its portion in slot226, out of action for the time being. At the same time, piston assemblyI l 8 is made efiective to close the door, if it is open, or to retainit closed, if it is already closed.

Now when a person approaches and operates the push plate or other devicefor moving bolt 296, switch 306 will be closed, energizing the solenoidcoil of switch 368 so that spindle 3l2 will rise, compressing thebellows and forcing air out of it. At the same time, the circuit isclosed across contacts 326 and 322, which is the circuit for thesolenoid of valve 292. Valve 292 will now open cylinder I26 to theexhaust port to discharge to the atmosphere. Thereupon the pressurebetween pistons I46 and H34 will cause piston assembly H8 to move tosuch position that the door will be moved to open position. If theperson holding the handle or other operating device has released thatdevice, or the device is moved with the door away from the hand of theperson, the operating parts of the mechanism will still go through theseries of steps defined for their operation, since switch 368 remainsclosed, as the time lag derived from the slowly falling spindle 312permits that circuit to remain closed for a time period determined inaccordance with the setting of member 328. Now, however, as the dooropens to its limit, as determined by the capacity of engine 54, therewill finally come the time when spindle 312 will return to a position tobreak the circuit between contacts 320 and 322. Immediately pressurewill be reestablished at valve 292, and piston assembly i [8 will nowmove to close the door.

If someone should come into contact with the door as it proceeds toclose, and any appreciable resistance should be set up to the return ofthe door to closed position, as, for instance, if someone should put outhis hand to hold the door against closing with the intention of goingthrough the door opening, that resistance will be sufficient to causethe loose motion which includes spring 86 to be compressed. Thiscompression of the spring also means that there will be resilient travelof the parts including that spring, so that switch H2 finally will beclosed. The closing of that switch closes a circuit through the normallyclosed switch 352 and again energizes the solenoid of switch 398, andagain energizes the coil of valve 292. Again the door moves to openposition, and repeats the cycle. This recycling of the door willcontinue so long as someone resists the movement of the door to closedposition, or if anyone should strike the push plate or otherwise operateswitch 396. Finally, however, the door will move to completely closedposition. Just as the door moves to engage the bolt in the strike, andthus necessarily to set up resistance at spring 86, it might causereversing of the closing movement. Switch 352 then goes into action.

Switch 352 may take the form of anysmall movement switch commonlyavailable, and may have a button 356 extending into position forengagement by a strike plate 360. The body of switch 352 may besupported in position upon plate 28 in any desired manner; it is hereshown as positioned upon one of brackets 286 so that its button is inposition to be engaged by strike plate 366 which is retained in an car364 formed as a part of or secured upon link 222. Plate 366 is formedwith a threaded rod 366 which, by means of nuts on either side of theear, may be locked in position. Also its position may be adjusted todetermine the moment at which switch 352 comes into effect. Thus, switch352 may be timed to break the circuit through switch H2 just as thatswitch is being actuated when link 222 and its associated parts havearrived almost at the very limit of movement as the door reaches thelast stage of pushing the bolt into the strike. This switch will breakthe circuit so that switch H2 is made ineffective to open the door againat that point.

Spring 266, throughout this operation. has been kept under control bythe actuation of piston construction 254 to the limit of its movementwith the energization of valve 284. If at any time there should be apower failure, so that valve 284 would close, then no air would besupshould be suppliedcontinuously to the app aratush l a. similar'result, will: occur; the; air; pressureagainstipiston25%:will1faih.thus-weleasinggspring; zseror. further; operation; in: themanner indicateda. Engine 54 will likewise be-releasedfrom;

theeaetion otthe-air under-pressuresandiwill- 111615".

resiststhe openingand closing; of: thBwdQOI by anyone by: hand,-. ortheoperation of: spring, 2 66-; to.c lose-the*door..

There. may some times; when it. is: desired. torI'BHWQTthBrHKPP3xK8JtUS10-fi: thisoperationnnder the: action, of. theelectric? circuit: and air pressures. The operator may obtainthezresulttdesired-by. moving switch 339mm the-position indieatedaaManual, in which case :alhof; terminalsnafifl; 340'.

and342: are.disoonnected, and-none of. the'functions-oi theeapharatussheretofore considered .a-ree carried out, except:- that: the.- dooroperatesv asa ordinary. spring. operated. door' under. controloffspring-616.-

At\ certain times, the? operator. maydesire to keep therdoon opencontinuously. For.- thispnre pose,- hezmoves SAVltOh33flqtO th8position-indie catediasfDoor, open! Now: a: circuit: is come pieted:across all ofi terminals; 33-8, 3.43 and 342-; The-rresultt is clearlyseem sinceenow; without. the-e benefit oi switches-M hand 3 $18, power.isi-supplieddirectlyto the selenoid coilssoiboth valves. 284. andi232hmeans-that. the door; will: move; immediately under the. action:- ofengine 54;. to; theeopen-iposition; Howewer, sin-see, current-mewmainseon the, coillattvalve' 292, without an-y're. lease,-..thewre1easeof pressure fIOI-Ik'CQHdtlit-ZOBw remains? constant; and. thedoon will,thereforea. remaintconstantly, openzuntil .switchs330 is-reset-. Jnstas:soon; as thezswitch issresetsta eithen oithe other positions, theconstant applicatiomofi currentqto-valve. 2.82 .willcease; and the;-door will tlrrenenter upon. its operationin the. mannerpreviouslyydiscussedt In Eiggs. l3 tot2l,..the inyention -isrshownlan...59 pliedtoa sliding deort. construction of this type, a door '368ris,carried by hangers .316 and 312%.. Wheels-r 3.74, mounted on ithehangera. ride. upon-.1 airaok 315 fixed;toaebasee plate H! mounted,above door opening; ass on wall 382- Also. mounted :on: platahl fitistadifierentialtpnenmatic, engine 3.84,. held: in position: by anysuitable-.- means; such as: clamps 385- A-.. rod. 38 8 extendsfromatheengine;

Ad-Jasenti its, end, rod.- 3&8" carries: a; reversing;

switch mechanism, 3%.; lmechanismv 399s may; comprise a sleeveSBA-having; athreaded. end-$31M" received upon the threaded); end- 336 1of rod 3&8; This threaded connection andza suitable. lochnnh mayprovide. for adiustmentsofi sleeve 392: with relation to rod... 3.8.8 todetermine. the: end posh. tion for. rod: 388.: and the operation ofswitch mechanism. 393; attthatendpositien... The end; 39-6,. terminates,in, av reduced, section, 33.8; which is threaded to receive: a-nut 40.0access to which. is. had; through. a: sidewopening id 2: in wallofsleevefiilfl: AspringAMds coiledraround section; 383;. and; abutssagainst Inuit imeat one end,- and against the shoulder011192,.bi11ttQI1-LQQ5, ,thebeatkt provided in: a-vvall 4.14 closing:the. endofz'sleevea 392;. The: periphery'of the nut maybe-formed; withaplurality of I notches. so that; by engage?- ment of a; screw driver.:or" similar implement: in: the notches; thenut: may be rotated andthus-ads just the eiiective' pressurecof; spring- 464 against button4'98. Beyondv wall 414, sleeve. 392.: may' havesecuredthereto,or'formedtherewith a-rhoole; member 6 having an opening M8through: whichextends an armzfiewvhich maybe formed: as apart-ofhanger-3'10.

Extending. laterally "from. sleeve 392' is an arnr; 422 having, an;opening in which is--,retained: a. contactor pin 426; By suitablemeans,,.such'as threads upon the pin, and lock nuts engaging the pin' andholding itin position with relation: to arm G22, the. position of head4284s adjusted-'- Withrelation to button Mil-of a. switch43l: which-.1may-beseoured in. position upon arm 4520:5(17th32t .button430%is-inlinewith head 428.

In: ordinary operation, springilllll: has enough; rigidity totransmitrforcederived fromrods 38 8: and: transmitted. thereto. by thefrmcti'oningv oi? engine-- 384,, in the mannerto bev described;, button408-,- andctherehy to-arm $20,, to move the; door. to-closed position;.If someone interposes: a. force to prevent operation of the door.tozclosed position. in the usuatmanner; the resistancestothe. closingmotion. of; theldoor, against the action of engine 384:, will. causebutton. 488* to..- movesv with relation to sleeve-.392, and compressspring; Me. If. the; resistance to. the. movementvcon tinues, head 428;,which. has: been; moving: with; relation to button 430,willtcausesw-itch43151281 be actuated, for; purposes; to be; described;..

Carried onarmm, above s1eeve.=39-2;.isa yoke;- 534, Trained through the.510121436 betweemthe; arms 01E. the: yolce may beans: suitable" band on"sprockets chain 438;v The chain, in-turn, isxtrai-x-ied; over a pair;oil sprockets-4 w; andAAZ: Sprocket; 442 may be. provided aib'earingon.;plater3'l8.. Car.-- ried by chain 4385may-besa;bloch'MAtpositionedso that, under circumstances; toabedescribeduthe block may comesinto.engagementiwiththeia'rms of. yoke 43%.

Sprocket; M0 isacarriediupon. a; shaftzflfiwhich; isprovided bearings"imasbearing body l4 fiz whi'chz forms-martin an;.auxiliarycdeviceg450.. Device-; 45.01. is. held in position 1. upompiate- 318 by any:suitable; means, as; for: instance; by: 01211111952452; encircling:cylinder bodies- 4 54'" and- 45 E whichexe tend awayfrom..bearing;body;-448 Bearing body- 44,8:may be formed asascoupl'ingzha-ving.thread;-

edv portionsinto which bodies: 454:- and: 456m anee. received...Withimbody-AAS; shaftz lefi hassatgear.

458 fixedto rotate. therewith; the; gear: being; ens meshed. withiaracle4:60;.

At oneiend;,,withinzcylinden body; 451%, rackrdfinii is. formed.orsotherwise madea'up; to; provide: aspin. l 62 the pin. hasmountettthereon and: SEOHIESd-i theretothe elementssof; a piston:v dfieswhich;may include aeleather cup 46.6.- andsuitabie compnes:.- sors; forholding. the leather: czup in. placeupon: the pin. That pistoniszslidable within: cylinder 1 body; 454 for? moving thevrac-k: undertheaction'.

of; air. obtained, from; a; conduit. tfiai-conneotedii toanv opening;thin; accapz llz closing; the end of cylinder' lede. Conduit fisrleadsto asouree as air pressure; which iSe under: controls tobe de scribedfurther:

Rack; 46!} extends beyond cylinder: 454'; and 'be yondi the; body, 448,,to terminatetinan: end: pin ldgsecured; in. connection; withaz guidedisk: 411:;

This disk serves asan'endsmemhenagainst which 456, which may be closedby a'cap 480 against which the other end of spring 418 bears. That capmay have an opening 482 to provide free communication at all times fromthe interior of cylinder 456 directly to the atmosphere.

' The apparatus may be supplied with air under pressure from a suitablesource. That source ma be directly coupled to conduit 468 so that, solong as air under pressure is being supplied to the apparatus, piston464 will be driven into cylinder 454 to its limit of movement, thuscausing rack 460 to move disk 476 to compress spring 418 within cylinder456 and simultaneously to rotate gear 458, and move block 444 to itsposition at the extreme right-hand end of its movement, as shown in fulllines in Fig. 13. In this position, as yoke 434 moves with door 368, theyoke will not engage or be engaged by the block. However, in the eventof failure of air in conduit 468, rack 460 will drift to the right asspring 478 overcomes the action of piston 464. This movement will causeblock 444 to move to the left. If the door is closed, nothing willhappen during this stage of movement. If, however, the door is open,spring 418 will be efiective to move the door to closed position. Then,in either case, if someone should desire to move the door to openposition, he need merely grasp the door and push upon it in the normalmanner to move it to open position. Such exertion will cause the door tomove to open position, but against the resistance of spring 478. Sinceair is not being supplied to the apparatus, engine 384 will take no partin this operation.

The source of air from the reservoir, indicated by conduit 468, alsoconnects with port 484 which communicates with chamber 486 in housing488 forming a part of engine 384. Through a passage 490 in housing 488is movable rod 388. At one end of housing 488, passage 490 is enlargedfor the reception of packing 500 held in place by a suitable cap 502.

Beyond housing 488 in cylinder 504, a piston structure 506 is assembledupon the end of rod 888. This structure may take any desired form,preferably including a leather cup 508 and packing retained in positionin any desired manner. Air entering housing 488 and into chamber 486will tend to move piston structure 506 through cylinder 504 toward cap5| 2. Cap 5l2 which closes the end of the cylinder has a passage 5I4with which communicates a conduit 5l6 from a magnet valve 518. The valvepreferably is of the exhaust type, and is positioned to govern thesupply of air from conduit 468 to cylinder 504.

When valve 518 is energized by the circuit to be I discussed, it opens aport from cylinder 504 to the atmosphere, and cuts oil flow of air fromconduit 468 to the cylinder. Air within cylinder 504 may then exhaust tothe atmosphere. such case, the compressed air constantly supplied tochamber 486 through port 484 will become efiective to drive rod 388 to aposition to open door 368. Carried by rod 388 is a valve member 520which is slidable in bore 522 within rod 388. A sleeve 524 threadedlyreceived in bore 522 serves as an end stop for a washer 526 held at theend of member 520 within bore 522 to limit the movement of member 520with relation to rod 388. Spring 528 :within bore 522, engaged againstwasher 52 6, and at the other end against the sealed end of bore 522,serves to retain member 520 projected from bore 522.

1 At the free end of member 520 a pair of valve The rod may be made oftubular metal. 7

seating members 530 and 532 are held in place by any suitable means. Atcap 5| 2, a seat 534 is provided for engagement by member 530. Thus, aspiston structure 506 moves toward cap 5l2, air has first been exhaustedfrom cylinder 504 by the opening of the port to the atmosphere by valve5l8. However, member 530 quickly engages seat 534 and closes off theopening through the cap against free movement of air from cylinder 504.A by-pass 536 is provided through cap 5| 2 into passage 5l4. Thuscontinued movement of piston structure 506 will be cushioned by airtrapped in cylinder 504, and as it leaks through by-pass 536. thecylinder will be expelled, and seating member 532 will be covered overand engaged by sleeve 524 at the very limit of the opening movement ofthe door. When pressure is reestablished in cylinder 504 bydeenergization of valve 5| 8, rod 388 will be driven to move the door toclosed position by the air entering through pas-' sage 5I4 and causingpiston structure 506 to overcome the pressure in chamber 486 against thesame piston structure.

To control the movement of the door, to prevent slamming and to permitthe engine sufficient time in which to cause the door to coast to theend position, an electrical circuit arrangement is associated with thedoor, and made efiective by the movement of the door. Current issupplied to the apparatus from a power source through mains 538 and 540.A suitable main cut-01f switch 542 may be positioned to control thecircuit by controlling one of the mains. Fixed to be carried betweenhangers 310 and 312 is an insulating base 544 upon which are arranged aplurality of tracks 546, 548 and 550. Carried by and insulated fromplate 318 and suspended so that, by their independent springs, they willmake contact with the respective tracks, are a plurality of shoes orbrushes 552, 554 and 556, which thus remain stationary with relation tothe door opening. One main 538 is connected to brush 554. The other mainis connected, through the coil of a time delay unit 560, with brush 556.

All of the brushes are in engagement with their respective tracks 546,548 and 550 at all times. However, track 546 (top) consists of twosegments, one a conducting segment 562, and the other a non-conductingsegment 564. Segment 564 is at the position where brush 552 will engageat the end of the opening movement of the door. Segment 562 isconnected, by means of a jumper 565, with track 548. Track 548 isconnected to one side of a switch 566, which may be a part of a doorplate 568 located upon the door. This operating plate may be carriedupon the door panel beside the door, if desired. However, in theconstruction shown, the switch is carried by and is movable with thedoor. The other terminal of this switch is carried to track 550. Now, ifsomeone should actuate this switch by manipulating plate 568 in any wellknown manner, a circuit will be closed through tracks 548 and 550,through the respective brushes and the coil of the time delay unit 560,which is thus energized to close switch 510, and at the same time tocharge a condenser or, in some similar manner, as, for instance, asdescribed for switch 308, to build up a delay for the operation ofswitch 510 to permit the switch to remain closed even though the circuitat switch 566 should now be broken.

With the closing of the circuit at switch 5l0,

Finally, all of the air in power passes to energize valve 8, and engine384 is energized to open the door, the opening action of the door beingcushioned in the manner heretofore described. Brushes 552, 554 and 556move over their respective tracks. At the same time, switch 431 isreleased by disengagement of head 428 from button 430.

One lead from switch 510 goes to the coil of valve 518, while the otherlead from the coil of valve 518 goes to brush 552. This brush will rideover track 546. Therefore, at the end of the opening movement for thedoor, brush 552 will ride onto non-conducting segment 564, and break thecircuit for valve 5l8. Thus, in the event that time delay unit 569 isnot functioning to break the circuit at switch 510 by the time the doorhas moved to fully open position, or if, for some reason, the openingmovement of the door is not completed within the time for which unit 560is set, the break in track 546 will function as a limit switch, as thebrush rides to the non-conducting segment 554, cutting valve 518 out ofcircuit. The door will coast to a halt, against the now reversed effortof engine 384, and then engine 384 will move the door reversely toclosed position.

On the other hand, switch mechanism 390, on the door, is connected inseries circuit with circuit cut-out switch 512 which functions in thesame manner as switch 352 (Fig. 12), that is, to cut switch 43| out ofcircuit when the door reaches the end of its door closing movement.Switch 512 is normally closed so as not to interfere with thefunctioning of switch 399 to reverse the door closing movement when someforce prevents the closing of the door except at the very last moment ofthe door closing movement. This switch, in this case, is shown mountedupon the door, while the actuator for the switch, that is, a springpressed strike button 514 to move it to break the circuit for switch43l, is slidably carried upon the door frame. Thus, when the doorreaches the end of its closing movement, switch 512 is opened first,before switch 43! can be actuated, and. thereby switch 43! will be madeineffective. This circuit including switches 43! and 512 is connected inparallel circuit with switch 566.

If resistance is encountered to the closing movement of the door, switchmechanism 390 will close the circuit through the normally closed switch512 to energize the coil of time delay unit 5911, thereby to energizevalve 5l8. However, at the end of the closing movement, as the doorapproaches completely closed position, switch 512 is caused to open, inthe manner previously discussed, and thus actuation of switch mechanism399 with the closing of the door will be ineffective to operate timedelay unit 569 for causing the door again to open.

It can be understood that the motive means for opening and closing thedoor, and for placing the springs under compression until failure occursmay take the form of operating means other than pneumatic engines. Forinstance, hydraulic engines or electric motors may be substituted forthe pneumatic engines here described.

Many other changes could be eifected in the particular construction, andin the methods of use and construction, and in specific details thereof,hereinbefore set forth, without substantially departing from theinvention defined in 18 the claims, the specific description beingmerely of an embodiment capable of illustrating certain principles ofthe invention.

What is claimed as new and useful is:

1. In combination, a door, means for resisting and yet permitting theopening of the door but normally tending to move the door to closedposition, means for moving the door to open position independently ofany resistance on the part of said resistingmeans, a source of energyfor the door opening means, means for controlling the energy from thesource to the door opening means, and means for applying energy fromsaid source to said resisting means to make the resisting meansineffective so long as the source of energy remains effective.

2. In combination, a door, resilient means for resisting and yetpermitting the opening of the door but normally tending to move the doorto closed position, means for moving the door to open positionindependently of any resistance on the part of said resisting means, asource of energy for the door opening means, means for controlling theenergy from the source to the door opening means, and means for applyingenergy from said source to said resisting means to make the resilientmeans ineffective so long as the source of energy remains effective.

3. In combination, a door, a spring for resisting and yet permitting theopening of the door but normally tending to move the door to an endposition, means for operating the door to either of a plurality of endpositions independently of any resistance on the part of said resistingmeans, a source of energy for the operating means, means for controllingthe energy from the source to the operating means, and means forapplying energy from said source to said resisting means to make thespring ineffective so long as the source of energy remains effective.

4. In combination with a door movable with relation to a doorway, a pairof engines, mechanism for imparting movement to the door away from andtoward open-barrin position, means capable normally of imparting forceto the mechanism to move the door in doorway-closing movement, one ofthe engines being arranged to move the door positively through themechanism, the other engine being arranged to counteract theforce-imparting means, and means for supplying energy simultaneously toboth engines to leave the first engine free to control movement of thedoor to its various positions while at the same time constituting thesole instrumentality for maintaining said force-imparting meansinapplicable to move the door.

CYRUS W. BASSETT. JOHN H. VANDER VEER. ALBERT E. WEIGELE.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,037,267 Knight Sept. 3, 1912 1,874,903 Conway Aug. 30, 19321,928,698 Morris Oct. 3, 1933 1,946,577 Fazendin Feb. 13, 1934 1,949,645Conklin Mar. 6, 1934 2,127,376 Purdy Aug. 16, 1938 2,130,764 ConklinSept. 20, 1938 2,343,316 NewKirk Mar. '7, 1944 2.504.408 Griffin Apr.18, 1950

